Scientists in Japan are carefully analyzing a few grains of rock from a spacecraft that returned to Earth in June. They’re trying to find out whether the grains are from Australia, where the craft landed -- or from an asteroid.

Hayabusa -- Japanese for “falcon” -- briefly touched down on asteroid Itokawa five years ago this week. It was supposed to fire two pellets at the asteroid to stir up some dust, which would settle in a small collection chamber aboard the spacecraft.

The pellets didn’t fire, but there was hope that the impact of Hayabusa itself stirred up a few particles. After the craft returned to Earth, scientists did indeed find some grains in the collection chamber. But they’re trying to figure out whether the grains came from Itokawa or from Earth. If they are from Itokawa, they’d be the first samples of an asteroid ever captured from the asteroid itself.

Hayabusa was a remarkable achievement in engineering and in perseverance. Its solar panels were damaged by a solar flare, which delayed its arrival at the asteroid. Yet it managed to fly beside Itokawa for months, snapping pictures and taking other readings.

Technical glitches made the craft hard to control and communicate with. Yet engineers managed to achieve the touchdown, then set Hayabusa on its way home -- on a path that took three years longer than planned.

Now, scientists are taking the final step: determining whether the falcon snared bits of an asteroid.